Stem cell research is coming of age in China

<正>In recent years,stem cell research has become one of the most exciting and promising biological fields,which offers great opportunities for curing many diseases that are currently recalcitrant to traditional clinical approaches.     

Stem cell research in China

In the past 5 years, China has increased its efforts in the field of stem cell research and practice. Basic research mainly focuses on bone marrow and embryonic stem cells. Clinical applications of stem cells in the treatment of acute heart failure, acute liver failure and lower limb ischaemia have been reported by many hospitals. China enacted its 'Ethical Guidelines for Human Embryonic Stem Cell Research' in 2003. At present, China has the most liberal and favourable environments for human embryonic stem cell research.     

Stem cell research in Singapore

Singapore is investing heavily in stem cell research. This investment is part of an ambitious biomedical science initiative designed to enhance its thriving economy.     

Stem cell research in the Emerald Isle

Fiscal policy, governance, education and a more internationally integrative strategic policy significantly assists Ireland's competitiveness in stem cell R&D sector.     

Stem cell research in Brazil: a difficult launch

It has been one year since Brazil passed a law enabling scientists to work with human embryonic stem cells and to derive new stem cell lines from human embryos. But several major hurdles have put human embryonic stem cell research on hold.     

Stem cell fate in proliferating tissues: equal odds in a game of chance

Quantitative lineage tracing reveals stem cell fate in?vivo. A new study in a recent issue of Cell shows intestinal crypt stem cells are functionally equivalent, with equal odds of differentiation. Differentiating stem cells are replaced by the symmetric division of adjacent stem cells.     

Stem cell research goes underground: the RETINOBLASTOMA-RELATED gene in root development

Both cellular differentiation and stem cell maintenance must occur at the root apex in order to ensure the continuous growth of plant roots. In this issue of Cell, it is revealed that a canonical retinoblastoma pathway plays a crucial role in regulating the balance between differentiation and renewal of plant root stem cells.     

Stem cell research: its relevance to reproductive biology

Stem cells provide an excellent model system to understand the differentiation, development and functioning of gonads, and further use of these cells in transplantation or cell-based therapies. Embryonic germ cells present as a better source of pluripotent stem cells. The germ cells are specialized cells, which differentiate into sperm or oocytes. Spermatogonial stem cells are the only stem cells in the adult mammalian body that can be recognized and studied at cellular level with respect to proliferation and differentiation. In the present study, basic process of spermatogenesis, testicular niche and molecular regulation of spermatogenesis and density regulation has been discussed. Research on oogonial stem cells has recently been encouraged due to the demand for oocytes for various research purposes. Mechanism of regulation of follicle formation, oocyte attrition and follicle development and atresia are only partially understood. Hence, the stages of development, its interaction with the neighbouring somatic cells during each developmental stage and the molecular regulation underlying it has been reviewed. These studies will result in establishment of treatment of ovarian disorders, and in identifying cure for infertility that occurs due to ovarian pathophysiology. Indian scenario in terms of stem cell research and its benefits is also discussed.     

Lead exposure in free-flying turkey vultures is associated with big game hunting in California

Predatory and scavenging birds are at risk of lead exposure when they feed on animals injured or killed by lead ammunition. While lead ammunition has been banned from waterfowl hunting in North America for almost two decades, lead ammunition is still widely used for hunting big game and small game animals. In this study, we evaluated the association between big game hunting and blood lead concentration in an avian scavenger species that feeds regularly on large mammals in California. We compared blood lead concentration in turkey vultures within and outside of the deer hunting season, and in areas with varying wild pig hunting intensity. Lead exposure in turkey vultures was significantly higher during the deer hunting season compared to the off-season, and blood lead concentration was positively correlated with increasing wild pig hunting intensity. Our results link lead exposure in turkey vultures to deer and wild pig hunting activity at these study sites, and we provide evidence that spent lead ammunition in carrion poses a significant risk of lead exposure to scavengers.     

Governing stem cell research in California and the USA: towards a social infrastructure

Owing to the restrictive human embryonic stem cell (hESC) policies of the US government, the question of whether to pursue human embryonic stem cell experiments has dominated the ethical and political discourse concerning such research. Explicit attention must now turn to problems of implementing the research on a large scale: in the 2004 US elections, California voters approved a state initiative for stem cell research, earmarking $3 billion in direct spending over 10 years. This article explores three ethical and political problem areas emerging out of the California program, the resolution of which will help set the trajectory of hESC research in the US and abroad, and then proposes an institutional approach to help address them: a network of public stem cell banks in the US that feature transparent and shared governance.     

Stem cell self-renewal: centrosomes on the move

Three recent studies show that centrosome asymmetry correlates with self-renewal of Drosophila neural and germline stem cells and that equalizing centrosomes disrupts asymmetric cell division.